Template talk:Convert/Archive October 2019

Conversion: EUR/USD

The cost of one euro in US dollars (from 1990).

• Moved from Help talk:Convert messages. Johnuniq (talk) 05:41, 3 October 2019 (UTC)

Greetings. How do I make a conversion from EUR to USD? I got error messages for each one of the following: EUR, USD, €, and $. Please find below the syntax that I tried:

• {{convert|10|€|$}} million
• {{convert|10|EUR|USD}} million

Thanks a lot in advance! Cheers! — Preceding unsigned comment added by Jayaguru-Shishya (talk • contribs) 20:01, 2 October 2019 (UTC)

@Jayaguru-Shishya: I moved the above to here because this is the place where how-to convert issues are discussed. By the way, your comment was made at 20:01, 2 October 2019 yet no timestamp appears in your signature—perhaps you accidentally used three tilde characters rather than four.

Convert has no way of converting between euros and dollars; all convert can do is convert things like $/acre to $/ha. I do not know if any template can handle converting euros to dollars—the conversion rate can vary each day and the rate that applies now might not have been the rate that applied when the amount specified was used. Johnuniq (talk) 05:41, 3 October 2019 (UTC)

Jayaguru-Shishya, see chart (inserted above) for how impossible it would be to do what you want. But would Template:Exchange rate serve your purpose? It only gives pointers to today's rates. If you want the rate on a specific date, OANDA.COM provides such a facility for (I think) the most recent ten years. --John Maynard Friedman (talk) 11:51, 3 October 2019 (UTC)

{{Exchange rate}} only gives the exchange rate on the day that the reader is looking at it - which might be years afterwards. It also doesn't flow very well in the text. If an event happened in 2004, I write about it in 2019 and somebody reads it in 2027 then the exchange rate can be drastically different in each case and the reader will not know which rate was intended. Therefore we need to write it like "the widget cost US$20,000 (€18,200 at October 2019 exchange rates)" or "the widget cost US$20,000 (€12,200 at April 2004 exchange rates)" The editor will have to find the actual exchange rate for the intended date manually unless the source happens to provide both figures for you. {{currency}} can be used to show other currencies but it too cannot do conversions.  Stepho  talk  19:52, 3 October 2019 (UTC)

Stepho-wrs My apologies, I must have got distracted and completely forgotten the time value of money. A conversion based on the spot rates would be rather easy, but well ... completely irrelevant tomorrow :-) Cheers! Jayaguru-Shishya (talk) 17:54, 4 October 2019 (UTC)

No worries, it's a common misunderstanding.  Stepho  talk  19:27, 4 October 2019 (UTC)

Suggestion: Comparing to the speed of light?

I would like to propose adding c as a unit for the speed of light, if it is feasible/wanted. I am thinking being able to use something like {{convert|0.3|c|km/h mph|abbr=on}} or {{convert|1.2e8|km/h|mph+c}} as examples. For things that are moving very quickly, this could be a useful comparison. As a point of comparison, ly is defined for light-year, so I think this would fit in the same light, as it were. Nutster (talk) 07:22, 8 October 2019 (UTC)

This was previously discussed at December 2017 and April 2018. Those discussions did not show an example of where a new unit would be used, and there was some talk that c might be used inappropriately. Any thoughts? Johnuniq (talk) 08:21, 11 October 2019 (UTC)

My knee-jerk reaction was 'well, of course we should'. But the previous discussions convinced me that it is not justified. --John Maynard Friedman (talk) 10:05, 11 October 2019 (UTC)

Conversions of dry volumes

For User:Peter Horn/Sandbox#Odds and ends

• 20,000 dryqt, 20,000 dryqt
• 5,000 drygal, 1,000 dryoz
• 5,000 bushel, etc
  Peter Horn User talk 19:30, 14 October 2019 (UTC)

Peter Horn, the complete list of symbols recognized by convert is at Module:Convert/documentation/conversion data. You need to use USdryqt for dry quart and USbsh for bushel. The dry pint is the smallest such volume measurement recognized in the USA, though the term dry ounce is sometimes mentioned in cooking. StarryGrandma (talk) 20:58, 14 October 2019 (UTC)

@StarryGrandma: Thanks for the leg up. I'll study that list carefully. Peter Horn User talk 21:12, 14 October 2019 (UTC)

Spelling and WP:COMMONALITY

I know that in the past, it's been argued that the sp parameter has been included because of WP:ENGVAR. But there's a policy even more relevant: WP:COMMONALITY. "Metre" and "litre" are acceptable in American English (in common usage and especially legally; 1 2 3 4), they're just not preferred. However, "meter" (used in the sense of the fundamental unit of length in SI) and "liter" are unacceptable in all other variants of English. Given this, is the sp parameter still relevant? My recommendation is to get rid of it in the spirit of WP:COMMONALITY. Getsnoopy (talk) 23:04, 18 October 2019 (UTC)

Being a veteran of many ENGVAR wars, I can tell you that most Americans will fight that proposal to the bitter end. Most of them don't know that "metre" and "litre" are legal spellings for them and many still don't know that they are legal spellings for the British (so many times I have reverted those edits labelled as "typo"). But I wouldn't blame them for fighting this proposal - I would do the same if you proposed to used only the "meter" and "liter" spellings. Regardless, it's a policy matter that should be argued at WP:ENGVAR.  Stepho  talk  23:19, 18 October 2019 (UTC)

@Stepho-wrs: Well ignorance isn't a valid factor in shaping policy, so I would blame them. And there's nothing wrong with learning something new; after all, that's exactly what WP is about. "Metre" and "litre" are official, international spellings, not merely British spellings. But either way, I don't think this is a WP:ENGVAR conversation since I respect WP:ENGVAR as a policy. I just think those particular SI units should be spelled the way everyone would know and understand them, instead of only a select few in some cases. So that would put the issue squarely in this template's domain. Getsnoopy (talk) 01:24, 19 October 2019 (UTC)

This relates to an attempt to break WP:ENGVAR at Wikipedia:Village pump (policy)#American or British spelling? Neither. (permalink). The merits of the underlying arguments are not relevant. The point is that we rely on volunteer editors who spend considerable time and energy in creating good encyclopedic content. Such talented contributors often come with an opinion on how words should be spelled and the purpose of ENGVAR is to avoid driving them away with pointless bickering over whether something is 12 meters long, or 12 metres. Fortunately ENGVAR is widely accepted and will not change regardless of whether people who like a particular variant are wrong. Johnuniq (talk) 01:39, 19 October 2019 (UTC)

@Johnuniq: No, it doesn't relate; they're entirely separate issues. And apparently, having a civil, logic-based discussion about a policy proposal is tantamount to "an attempt to break" a policy proposal. "The merits of the underlying arguments are not relevant."—this statement is quite illuminating, as is the statement, "regardless of whether people who like a particular variant are wrong". Getsnoopy (talk) 18:11, 20 October 2019 (UTC)

Suggestion: Include angle conversions (NB possible conflict of symbols)

I suggest including conversion of angles in this template, as I regularly have to manually convert between milliradians and arcminutes when writing articles. The only possible problem I see is that the unit of absorbed radiation dose Rad (unit) (a non-SI unit, symbol: rad) is currently included in the template, and unfortunately has the same symbol as the Radian (SI symbol: rad). Some units I would like to see included are:

• Radian, with SI prefixes like mrad for milliradian, μrad for microradian, nrad for nanoradians, etc. Milliradians are commonly used in firearms, and astronomy commonly uses micro and nanoradians. Related units such as NATO mil, Warsaw Pact mil and Swedish streck should maybe also be included for convenience.
• Degrees (SI symbol: ° or deg), minutes (SI symbol: ′ or arcmin) and seconds of arc (SI symbol: ″ or arcsec) are also used regularly in firearms and astronomy. Degree based angles are sometimes also used with SI prefixes, for example milli-arc second can be useful in many cases.
• There are also many other angular units that maybe should be included. turn and gradian comes to mind as useful. Maybe also hour (symbol h, equal to 15°).

Sauer202 (talk) 07:23, 28 October 2019 (UTC)

Here is a draft:

Plane angle (draft)

Unit code	Symbol	US symbol	Scale	Extra	Name	Plural name	US name	US plural name	Prefix	Default	Link
rad	rad		1		radian	radians			SI		Radian
natomil	NATO mil (slang, but probably preferred) or ₥ (old French compasses) or ‰ (Swiss military) or ¯ (German military) (more info here)		2π/6400		NATO mil	NATO mils				mrad	Milliradian#Definitions for maps and artillery
warsawmil	Warsaw Pact mil (slang, but probably preferred) or v (Finnish military, alternatively v) (more info here)		2π/6000		Warsaw Pact mil	Warsaw Pact mils				mrad	Milliradian#Definitions for maps and artillery
swedishstreck	Swedish streck (slang, but probably preferred) or v (Swedish military, alternatively v) (more info here)		2π/6300		Swedish streck	Swedish strecks				mrad	Milliradian#Definitions for maps and artillery
deg	°		(π/180)		degree	degrees				rad	Degree (angle)
arcmin	′		(π/10800)		arcminute	arcminutes			SI	mrad	Arc minute
arcsec	″		(π/648000)		arcsecond	arcseconds			SI	μrad	Arc second
grad	gon		(π/200)		gradian	gradians				deg	Gradian
turn	tr		2π		turn	turns				deg	Turn

Was also considering to include points of the compass, but that may not be suitable since a reading appears to have a large tolerance (?). Sauer202 (talk) 08:04, 28 October 2019 (UTC)

Previous discussions (which I haven't had time to look at yet):

• Template talk:Convert/Archive September 2015#Angle conversions
• Template talk:Convert/Archive March 2017#Angles

Please link to a couple of articles and quote some text where convert would be used. Johnuniq (talk) 09:05, 28 October 2019 (UTC)

Here are some articles where a template could be useful (search for "mrad" in the article).

• Target definitions: Shooting target, International Benchrest Shooters, International Confederation of Fullbore Rifle Associations
• Concepts of accuracy: Accurizing, Sniper rifle, Precision Sniper Rifle
• Sight adjustment: Telescopic sight, Diopter sight, Red dot sight
• Precision of firearm models: Steyr SSG 69, Heym SR 30, Accuracy International AWM, RPA Rangemaster, Desert Tech SRS, Blaser R93 Tactical
• Range estimation: Milliradian

Will have a look at the previous discussions later. Sauer202 (talk) 10:35, 28 October 2019 (UTC)

I've had a look at the previous discussions. One argument against including angles is a fear that people may start adding unnecessary conversions to articles.

• For example, in many mathematical articles it only makes sense to use radians, so if someone adds conversions to degrees in good faith, it may only result in added "noise" that has to be reverted. Unsure about this really becoming an issue.
• On a similar note, I am sure there are many articles about for instance maps and navigation where it's only natural to use degrees, and if someone add conversions to radians it may only result in "noise" that has to be reverted. Also unsure about this really becoming an issue.

Another topic was whether it could be wise to add the possibility of displaying the same unit in different formats, e.g. display degrees in both dd (decimal degrees) and DMS-format ((hour angle, i.e. hours:minutes:seconds or hours^h minutes^m seconds^s). For example:

1. {convert|20|deg|hms} could output "20° (1h 20m)"
2. {convert|20.5|deg|dms} could output "20.5° (20° 30m)"
3. {convert|20d30m|dms|deg} could output "20° 30m (20.5°)"

This option was deemed silly and WP:BEANS by one author, and I agree. It makes sense to stick to one format within an article. Still, separate templates exist for this use:

• Template:Deg2HMS
• Template:HMS2Deg

A third reason was that radians usually don't provide nice and round numbers when converted to degrees. For example, fractions of π should perhaps be included when converting nice degree numbers to radians, at least in mathematical articles. Some examples:

• 30° = π/6 rad
• 45° = π/4 rad
• 90° = π/2 rad

Corresponding decimal representations could be:

• 30° ≈ 0.52359877.. rad ≈ 0.52 rad
• 45° ≈ 0.78539816.. rad ≈ 0.79 rad
• 90° ≈ 1.57079633.. rad ≈ 1.57 rad

While I in principle would like to have a "degree to radian" conversions, and vice versa, (both available in decimal and fractional), it probably is not needed very much at this time.

My conclusion is that only conversions back and forth between mrad and arcmin is needed. In the firearms literature where these conversions are used, rounded decimal representations tend to be more used than fractions, often with one more digit for the mrad value. If these conversions can not be included here in the Convert Template, an alternative is to put them into separate Templates, i.e.

• Template:mrad2arcmin
• Template:arcmin2mrad

Sauer202 (talk) 20:04, 28 October 2019 (UTC)